Sudden Error in Checkout Process

Sudden Error in Checkout Process

Dear Friends,

Successfully built a store for client using eCart 5, and all was running smoothly until today, when the following error message appears in the checkout process, after the visitor completes the shipping and billing page:

*******Transaction Not CompletedWe're sorryYour transaction could not be completed. Please go back and make sure all billing and shipping information is filled in.*******

Trouble is, all billing and shipping info has been filled in. Here's the URL to the store site:

If someone could direct me to possible causes (again, no one touched the code or server), or let me know what specific files would need to be reviewed for troubleshooting, I would greatly appreciate it!

Thanks, Jason!

I'll follow up with the payment gateway (Authorize.Net) — as stated earlier, no one touched the page code so I was hoping this was the culprit. I'll be sure to detail whatever the resolution is to hopefully help anyone else who encounters this problem.